Stephen William Hawking

British cosmologist Stephen William Hawking was born in England on Jan. 8, 1942 — 300 years to the day after the death of the astronomer Galileo Galilei. He attended University College, Oxford, where he studied physics, despite his father's urging to focus on medicine. Hawking went on to Cambridge to research cosmology, the study of the universe as a whole. 

In early 1963, just shy of his 21st birthday, Hawking was diagnosed with motor neuron disease, more commonly known as Lou Gehrig's disease or amyotrophic lateral sclerosis (ALS). He was not expected to live more than two years. Completing his doctorate did not appear likely. Yet, Hawking defied the odds, not only attaining his Ph.D. but also forging new roads into the understanding of the universe in the decades since.

As the disease spread, Hawking became less mobile and began using a wheelchair. Talking grew more challenging and, in 1985, an emergency tracheotomy caused his total loss of speech. A speech-generating device constructed at Cambridge, combined with a software program, served as his electronic voice, allowing Hawking to select his words by moving the muscles in his cheek.

Just before his diagnosis, Hawking met Jane Wilde, and the two were married in 1965. The couple had three children before separating. Hawking remarried in 1995 but divorced in 2006.